[willnbirdie]

Hi

We have worked our allotment for 2 years now and we still have one area of the garden with soil so clay-like after the recent rain that I could have hired a potters wheel and been well away!!!!

Can anyone please enlighten me as the best way to improve this patch of soil - we have added well rotted manure in previous seasons but would be interested if there are any other ideas that we could try this year.

Thanks for you help

willnbirdie

[gardener247]

llots of sand did the trick for me its nice and friable now... oh and lots and lots of manure

[raymo1]

Hi, Iv'e got the same problem. What sort of sand do you recommend? Thanks for any help.
Best Wishes,Raymo

[gardener247]

i used ordinary builders sand cause it was cheap but sharp sand might be better

[Swing Swang]

I would say that it must be sharp sand (or horticultural sand if you've got £££s). This is gritty and will improve drainage, whereas builders sand is much smoother, will compact more readily and will not achieve the desired effect so efficiently (if at all). I used sharp sand as a 4" mulch, it kept the weeds at bay for a season, then got dug in during normal winter digging.

SS

[gardener247]

yes ss is probably right i dont stand on my soil which makes it okay

[Trillium]

Also plant a green manure crop on off seasons, something like grazing rye or buckwheat, etc. Their roots break up the soil nicely  and you simply leave the dead stalks on the ground then later rotovate them in. Broken straw is also good fiber for the soil.

[zazen999]

I would say that it must be sharp sand (or horticultural sand if you've got £££s). This is gritty and will improve drainage, whereas builders sand is much smoother, will compact more readily and will not achieve the desired effect so efficiently (if at all). I used sharp sand as a 4" mulch, it kept the weeds at bay for a season, then got dug in during normal winter digging.

SS

But any sand is better than no sand if that's all you've got - as it is clay we are trying to add drainage to.

[Swing Swang]

Sorry Zazen999 but I'd disagree with your last comment - if I could only get builders' sand I'd reject it in favour of rotted manure/compost and take the long view. If you really compact builders' sand then water will puddle on it, whereas if you compact sharp sand/horticultural grit it won't. Adding tonnes of sand to you soil is a permanent alteration, and if you get it wrong you won't be able to undo your mistake.

SS

[zazen999]

Sorry Zazen999 but I'd disagree with your last comment - if I could only get builders' sand I'd reject it in favour of rotted manure/compost and take the long view. If you really compact builders' sand then water will puddle on it, whereas if you compact sharp sand/horticultural grit it won't. Adding tonnes of sand to you soil is a permanent alteration, and if you get it wrong you won't be able to undo your mistake.

SS

Sorry, but I disagree. If you have clay soil and you want to add drainage; any sand is better than no sand. You won't be puddling on it as it gets distributed and adds much needed air pockets and drainage. I have spent 14 years as a materials engineer testing soils and they do not behave the same way once mixed with other materials.

If you reject the sand, in favour of manure - can I have it?

[WARDDRU]

Hi,
    I used Agricultural Gypsum and it worked a treat. Have since found a bulk supplier called Rootwise. Lots of info on the web regarding this product.

www.rootwise.co.uk
                                     Regards Steve.

[Christine]

Can anyone please enlighten me as the best way to improve this patch of soil - we have added well rotted manure in previous seasons but would be interested if there are any other ideas that we could try this year.
willnbirdie

Been there and suffered that - you describe one half of my plot exactly. At the end of the first season, I took the hard way and double dug it in autumn and added some tonnage of manure and also sharp sand in the worst places. It improved it quite a lot but certainly didn't cure it for the next season. Second year I dug in green manure and added spent compost. It has had more spent compost and the addition of a large compost heap this winter. After three years it is beginning to be less like potters clay and more like soil.

Spent compost, home made compost and green manures are the cheapest options I can offer. The more manure you can gather if it's free the better. If it's as good a patch of potters clay as mine - well we are both looking at five years work realistically. At least it's not all the plot is it? That's the only good thing that comes to mind.

This is one of those things with allotments, you can spend time sorting out things that the previous tenants haven't done or didn't know how to do. The longer you have your plot, the better the improvements you can make. 

It will take more than a year to improve this patch of soil.

[Swing Swang]

OK Zazen999 I'll defer to your experience, but I'd want to experiment with it first before using it myself.

SS

[Kristen]

We have heavy clay. I've made "lazy beds" - poor-mans-raised beds, 4' wide, soil from the paths in between heaped onto the beds.  lower paths provide some run-off drainage. Rotavated the whole lot on Day 1, have done a bit of rotavating (with Mantis), and each year have put plenty of well rotted manure on (except the area for Roots). Other than planting and harvesting its had no further digging. I think the soil is surprisingly good already; the raised part of the beds has never been walked on. Haven't added any sand (reason = cost)

[mickeyboy]

OK Zazen999 I'll defer to your experience, but I'd want to experiment with it first before using it myself.

SS

Thats the way to go. Sharp sand is far more grity and break's the clay down well. Soft sand (used for laying bricks) holds water as it is far more dense than sharp sand. Add growmore, sharp sand and see how you get on.....